Matrix-retainer.



J. W. IVORY. V MATRIX RETAINER. AljPLIoATIoN FILED snPT.15, 190e.

@ln-venten lb a I Patented Feb. 2, 1909.

apertured at 2O for passage lof the screw. 16.

Avention in perspective. Fig. 2 represents JAMES W. IVORY, OFPHILADELPHIA, PENNSYLVANIA.

MATRIX-RETAINER.

Specification of Letters Patent.

Patented Feb. a, ieee.

Application :tiled September 15, 1908." Serial No. l153,102.

To all whom'it ,may'concerm v,

Be it known that I, JAMES W. IvonY, a subject of the King of GreatBritain, residing in the city and county of Philadelphia, State ofPennsylvania, have invented a new and useful Matrix-Retainer, of whichthe following is va specification.

The purpose of my invention is to con?- form a matrix to the shape of atooth.

For the purpose of illustrating my inven-v tion I havel shown in theaccompanying drawing, one form thereof which is at resent preferred byme, siiicethe same has een found in practice to give satisfactory andreliable results, although it is to be under stood that the variousinstrumentalities of which my yinvention consists can be variouslyarranged and organized and that my invention is not limited to theprecise arrangement and organization of these instru; mentalities asherein'shown and described.

Figure 1 represents one form of my ina similar clamp to Fig.V 1 in sideelevation, showing the matrix. Fio. 3 represents the same structure inlongitudinal section. F 4 represents a similar structure in top planview. Fig. 5 represents a modiiied form of my invention in sideelevation. 'Similar numerals of reference indicate. corresponding partsin the figures. Referring to the drawings :4 1 designates a base barwhich i-s bent laterally at one end at 2 and reversely bent atA 3 toprovide a space 4, while at theother end it is provided with a lateralface' 5 preferably curved at 6 to conformto the usual shape of a tooth'and apertured at 7 and 8, these spaces being separated by a bar 9. Thefaces 10 and 11 as well as the bar 9 are rounded to reduce the frictionof the band` or loop 12 thereon. The base bar islongitudinally slottedat 13 to provide a guide in which lthe screw 14 may travel, said screwpassing through the slot into the nut 15 within which the screw 16 isada ted topoperate. About the nut 15 I prefera ly form a easing 17having a jaw 18 at the front end thereof and a back 19 This-caslng 17ismost desirably rearwardly spring-pressed at 21 seas to bring its jaw18 in contact with the end of the screwf'l and4 make it follow saidscrew. Ilhe jaw 18-'00- operates with a jaw 2,2, 'which may be eitherintegral withfor separate from the lnut 15 but which is lpreferablycarried rigidly thereby, to produce a vise or clamp for the ends 23 and24 of the strap or loop 12.

It will be vevident that in the structure shown it is necessary for theclam i to be op pesite the apertures 7 and -8 and that the jaw 17 bewithdrawn from the jaw 22, dif* fering in these particulars from theposition shown in Fig. 3, in order that the ends 23 and 24 of the loopmay be threaded there-V through.

' The screw 16 is intended for a double purpose, both to tighten theclamping jaw of the vise upon the lends 23 and 24 of the loop or bandand'also to afford a means of longitudinal feed4 of this vise along thebase bar 1. vThis latter function is accomplished by ine'ansof a nut 25which is grooved at 26 and which is set within' an aperture 27 in thetransverse bends 2and 3 of the base bar in such manner that the groove26 shall in part coincide with the space between these transverse bendsorplates. The sci/ew 27 passing through the bend 28 of the base platefills up this aperture 26 at one point and prevents withdrawalof the nutlongitudinally, the same being4 free to rotate and by its rotation tocause the longitudinal movement of the screw 16 with the vise and strap'in their set positions. Complete withdrawal of screw 16 from nut 15 isprevented by screw 29 fitted into groove 30, which forms a neck in saidscrew 16 or other suitable means, said groove freely receiving saidscrew 29.

`While I have chosen to illustrate the form of the vise and thearrangement of the nut `shown it will be evident that a great variety ofthese mi ht be made use of for obtaining part of t ie benefit of myinvention andthat other forms or combinations than the bolt andoperating nut might be made use of to secure common adjusting andtightening means. i. I

In the form shown in Fig. 5,1 make use of an lindependent clamping screw31 to press the casing 3 2 against the ends 23 and 24, the casing beingspring-retracted at 1 The support or guide 35 mayA bev made use of -ineither of the forms. shown, in serving to hold the screw 30 and itsattachments parallel and steady.

It will be evident `that the screw im- -pinges against the casing 32 tomove it within the/loop to clamp or release'the ends '.23

and' 24 land that the spring 38 causes it toA les' vlongitudinallymoving the head follow up thescrew upon the release 4thereof. It isevident also that there isy no necessity for use of a screw lin thisform for .the purpose of tightening up the clamp, as its place issupplied by the screw 3l. The same function of the screw here providedof is present and the movement is providedby means of nut 25and-limiting screw 28, as in the other forms.

yHaving thus described my invention, what I claim as my invention anddesire to secure by Letters Patent, is:

jaws together.

'to said fixed jaw,

.1. In a matrix clamp, a base'bar, a slide movable longitudinally ofsaid bar, a pair movable longitudia spring normally separating saidjaws, slide and jaws longitudinally of said bar.

2. In a matrix clamp, a face adapted to engage with a tooth, a slidemovable with respect thereto, a jaw iixed upon said slide,

Ia jaw longitudinally movable with respect means for normally supandmeans for forcing theporting said jaws,

3. In a matrix clamp, a base, a vise mov.- able longitudinally thereon,a bolt operating and means to move the I einser Qaid vise, a nut throughwhich said bolt turns, and a support for said nut permitting rotationbut preventing longitudinal movement thereof along the base bar.

4. In a matrix clamp, a vise, a base bar, a nut, and a screw passingthrough the nut to tighten thea vise and permit advance thereof alongthe base bar by movement of the nut.

5. In a matrix clamp, a base bar, a vise movable thereon, and commonmeans for tightening the vise and longitudinally advancing it along thebar.

6. In a matrix clamp, a vise, a base bar, a screw engaging the vise toset the same,

means for advancing the screw andl vise longitudinally, and means fortion of said screw. f

f?. In a matrix clamp, a vise, a base bar, a screw engaging the vise toset the same, means for advancing the screw and vise longitudinally,and, means comprising a recess 1n the screw and pinl projecting thereinfor prreventing complete retraction of said screw om said vise.

` AJAMES W. IVORY. `Witnesses! W. S. JACKSON, JOHN A. y"Ninonneriann.

limiting retrac-

